Lamellate flat cell



Jan 19, 1954 v w. B. woDRlNG ErAL 2,666,802

LAMELLATE FLAT- CELL Filed Nov. 21, 195o FIG. l

Dara/armer ATTORNEYS Patented` Jan. 19, 1954 UNITED sTATEis PATENT OFFICE Y y accesos CELL "Willi-am TB, and William 'W.

:Delaware v y i'apliea'tiqniNvember 21, 195 o,.s`eria1iN6. .196.850

linvention frelatesfto ;c'irim'a ry cells and batteries Vand more,jpartic'i'ilarly to 'a'mivniature cells 'depending upon "electro-'chemical"'actionj to generate a current. ll'Vhi'le `"certain.fea'inir'e-s of the cell .may be employed toadvantage in A'cells of any lsizefthe most advantageous lform loi the invention is fa Yveneer thincejll 4in which" the elemerits are not only thin,'but a re1 at, that is, 'of substantiallyy uniform thickness throughout. the thickness 'being very "sinall compared to 'the "dimensions,

[Thus the cell, as Ydistingu'ished "from present consist of velements 'in the form or lamellae, 'and` the complete `cell 'mayibe'described Tasv 2a lamella'te structure.

to'fhave an 0unusually 'high capacity. This is probably due to extremely low internal resistancev becausev of the thinness'l'of the depolariz'ing layer.`

The lthinness rof this'flayer'alsopermitshighly eilicient utilization vofithedepol'ariz'en When the supporting' sheetfo'r the cathode coatingis formed-of '.metal, it and the 'metal anode, being heat sealed to the plastic frame, preventloss of moisture 'from the cell. It also provides excellent electricconnection .between adjacentcells of a battery by mere stacking of the individual cells, -a's the* construction produces metal `to `metal contact between the cells. y

In the accompanying drawing We have fshownl oney embodiment of the invention. `lIn this'showing:

Fig. v4l is a perspective .view of 'a fcell, on antenlarged scale, with the cathode supporting sheet partially raised .and with the other elements partially broken Vaway for clarity of presentation;`

and

ig. 2 is a transverse, *sectionall viewcn'line v2-2 of Fig. 1. f A

' TheV vcell comprising'-the "invention includes a zinc anode I in the -form of" aA 'sheet of'ioil. Around the periphery of the anode we provide a layerjZ of an'ac'lhesiveJ preferably a thermoplastic adhesive. A sheet of paper 3, which orrn's ase'parator' and which is of slightly .smaller dimensions'than the anode, is secured 'to tl'ie anode bythe adhesive. 2; As shown 'Cseelig .21l the adhesive layer extends 'inwardly vfrom 4the edge of the anode beyond the .outer edge'of the separator to permit sealing of the separat'orfto thezinc .foL A plastic frame 4, vwhich may be of slightly greater dimensions Vthan the anode, is arranged over the anode and the separator and is sealed to the anode by that portion' of the sensitive adhesive.

` centration of'an inhibitor, such as mecuric clilo cementflayer 2 which extends beyond. the s e'parator'. A layer of depolari'zing mix'i, oflvthe same 'height or thickness as 'the' thickness 'o the frame 4, is arranged Within l the frame. A cath-` ode supporting sheet 6,' Whic'hmay bea sheet oi zinc foil similar tothe anode,'is arranged on the opposite side of the frame. As showin, this sheet is provided with a cathode ycoatingl vwhich is conductiver and is .also a heat sensitive adhesive to sealtojthesur'face of the framed..

"The cells Amay 7beflof any desired cross section, for example, circular, square, Yrectangular o r elliptical and may also be of annular ofr'm. While the cell'may be of any desired size, the best results of the construction are obtainedv when the 4 cell is of. yveneer thickness. Thus, tlie plastic frame may be -of a thickness Yfrom .YOOVIM to.0.10 0. This frame 4may be made vof any' available material that uis dielectric and to which the cathode andanode may befsealed by a heat y Examples of materialwhich may be employed -f are polystyrene, cellulose acetate-butyrate, Vpolyvinyl chloride-.acetate zand similar materials The zinc toil forming the cathode may besecured to one side of .the frame and vto the paper separator by any suitable adhesive. A solution of approximately equal parts of VBuna N y(butadiene acrylonitrile copolymer) and a phenolic resin may be employed. The

paper separator is preferably coated on-one side with starch `and vimpregnatec'l with a low conride 'or'y sodium dichromate. The electrolyte vmay consistv ofjan' aqueous solution of zinc'chloride and yammonium chloride.

-The depolarizer lmay consistfof the y usual mix of 'manganese 'dioxide' and a conductive'carbon,l

suchas graphite or carbon black. 'Itm'aybe assembledf'as hereinafter set 4lforth. lieu fof the usual depolarizer, the mix 'cake vmaybe {in sheet form, that is, a'loosely Woven clothypaper or other suitable carrier, may be impregnated Withfthe depolarizing mix.

The cathode is preferably supported on a metal sheetjor foil but any electrically'conductive'supporting material, such as paper, cloth orthe/like, suitably impregnated, Vmaybe used. "Ihe-outermost layer of the cathode coating which contacts with the frame comprises a nlm of conductive heat sensitive adhesive which Will bond to the plastic frame. The zinc foil may be coated with a conductive electrolyte-impervious layer of a mixture of polyvinyl chloride, dioctyl phthalate,

and acetylene black and a conductive adhesive top layer of a mixture of polyvinyl acetate, tridiameter than the anode, is placed on the anode and caused to adhere to it, either by a solvent or heat activation of the adhesive. The electrolyte is then added. The frame is then lled with the depolarizing mix 5. If the mix is in ordinary form, it is placed in the frame andlevelled by a doctor blade. If the depolarizer is in sheet form, it is merely placed within the `frame. The cath` ode is then placed in position and caused to adhere either by heat sealing or by covering the contact area 'between the cathode and the frame with a solution of adhesive and pressing the parts together.

As stated, cells of such size and construction have been found to have unusually high capacity as compared with cells of usual construction containing the same amount of depolarizer, especially on continuous discharge at a heavy drain. Thus, a tested cell in which the elements were circular, the frame 4 being 6" in external diam- 9 eter, 5% in internal diameter, and 0.012 in thickness, and the anode and cathode 5%" in diameter, having an initial open circuit value of 1.81 volts and a closed circuit value when connected to a resistance of 2.03 ohms of 1.52 volts and .'75 ampere, after being on discharge for thirty minutes, had a value of 1.18 volts and .58 ampere. In addition, the cell possesses many other advantages. The cells can be aged individually and then readily tested before assembly into a battery. This permits discarding the single defective cell Without disassembling a battery into` which the cell has been assembled. The arrangement of the anode and paper separator with respeci; to the plastic frame prevents short-circuit- A. plastic frame 4, preferably of slightlygreater( 4 of zinc foil of larger dimension than the separator, the anode having a coating of adhesive adjacent its edge to secure the separator to the anode and the anode to the frame, a sheet cathode having a conductive coating on its inner surface sealed to the other side of the frame, and a depolarizer Within the frame.

2. A ydry cell comprising a thin, flat frame of .Y Y dielectric material of substantially uniform thickness, an anode ln'sheet form sealed to one side Vof vthe frame, a cathode in sheet form sealed to the other side oi the frame, and a depolarizer and electrolyte within the frame between the anode and cathode, the frame being larger than the anode and cathode and projecting beyond the edges of the anode and cathode.

3. A dry cell comprising a, thin, iiat frame of dielectric material of substantially uniform thickness havinga central opening, a separator carrying electrolyte on one side of the frame extending over the opening, the separator being larger than the opening and having its edge portions sealed to the frame, an anode comprising a sheet of zinc foil of larger dimension than the separator, the anode having a coating of adhesive adjacent its edge to secure the separator to the anode and the anode to the frame, a. sheet cathode having a conductive coating on its inner surface sealed tothe other sidev of the frame, and a depolarizer Within the frame.

4. A dry cell comprising a thin, nat frame of dielectric material of substantiallyuniform thickness having a central opening, a separator carrying electrolyte on one side of the frame extending over the opening, the separatorbeing larger than the opening and having its edge portions sealed to the frame, an anode comprising a sheet of zinc ing. The drying out of the cell is minimized by support is made of zinc and a plurality of cells assembled in a battery, if an anode vbecomes. perforated, the adjacent contacting sheet 6 serves as the anode of the defective cell and thereby lengthens the life of the battery.

As many of the so-called nat cells are not, in reality flat, we have chosen the term lamellate construction as more accurate in defining the cell of the present invention, the individual components of the cell being truly lamellae and the thickness of the cell being the sum of the thicknessof the anode, separator, cathode terminal and frame. As stated, the invention may be employed in connection with primary cell elements other than those of the Leclanch cell.

, We claim:

1. A dry cell comprising a thin, at frame of dielectric material of substantially uniform thickness having a central opening, a separator carrying electrolyte on one side of the frame extending over the opening, an anode comprising a sheet foil of larger dimension than the separator, the anode having a coating of adhesive adjacent its edge to Secure the separator to the anode and the anode to the frame, a sheet cathode having a conductive coating on its inner surface sealed to the other side of the frame,'and a depolarizer within the frame, the frame being larger than the anode and cathode and projecting beyond the edges of the anode 'and cathode.

5. A dry cell comprising a thin, nat frame of dielectric material of substantially uniform thickness, an anode in sheet form sealed to one side of the frame, a cathode in sheet form, having a conductive coating on its inner surface sealed to the other side of the frame, and a depolarizer and electrolyte within the frame between the anode and cathode, the frame being larger than the anode and cathode and projecting beyond the edges of the anode and cathode.

WILLIAM B, WOODRING. l WILLIAM W EATON.

References Cited in the le of this patent UNITED STATES PATENTS Number Switzerland Sept. 16, 1944 

1. A DRY CELL COMPRISING A THIN, FLAT FRAME OF DIELECTRIC MATERIAL OF SUBSTANTIALLY UNIFORM THICKNESS HAVING A CENTRAL OPENING, A SEPARATOR CARRYING ELECTROLYTE ON ONE SIDE OF THE FRAME EXTEND ING OVER THE OPENING, AN ANODE COMPRISING A SHEET OF ZINC FOIL OF LARGER DIMENSION THAN THE SEPARATOR, THE ANODE HAVING A COATING OF ADHESIVE ADJACENT ITS EDGE TO SECURE THE SEPARATOR TO THE ANODE AND THE ANODE TO THE FRAME, A SHEET CATHODE HAVING A CONDUCTIVE COATING ON ITS INNER SURFACE SEALED TO THE OTHER SIDE OF THE FRAME, AND A DEPOLARIZER WITHIN THE FRAME. 